JP3471313B2 - Friction stir welding equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction stir welding apparatus and method for softening and stirring objects to be welded by frictional heat generated by rotation.

[0002]

2. Description of the Related Art In friction stir welding, a pin having a pin at its tip is rotated at high speed while the pin is inserted into a work, and the work is softened and agitated by friction heat to join the work. In conventional friction stir welding, particularly spot welding, when the rotor is pulled up and the embedded pin is extracted, a cavity corresponding to the pin is formed at the welded portion.

When the cavity is formed in this way, stress concentrates on the cavity, and the joint strength decreases. In particular, fatigue fracture is likely to occur. In addition, the appearance is deteriorated, which is aesthetically unpleasant and causes stains. As described above, there are various problems in terms of use, which is a problem in product quality.

[0004]

In order to eliminate this cavity, for example, Japanese Patent Laid-Open No. 11-156561 discloses that
Although a method of embedding a hole filling material is disclosed, in this case, the embedding itself is difficult, and it is even more difficult to perform it at multiple points.

Further, Japanese Laid-Open Patent Publication No. 10-193140 discloses a method in which a pin is movable, and in continuous joining, a cavity is not formed by gradually pulling out the pin while moving, but in spot joining. It does not describe how to fill the cavity, nor can it simply be applied to spot bonding.

Further, in this method, the shoulder portion is pressed by using the spring force, the pin is gradually pulled out, and no pressing force is generated at the joining end point of the continuous joining,
There is a problem that the joining quality at the joining end point deteriorates.

It is an object of the present invention to provide a friction stir welding apparatus and method capable of joining without forming a large cavity by a pin.

[0008]

According to the present invention, a rotor that rotates at a high speed is moved in the direction of a rotation axis to press the tip end of the rotor against an article to be joined, so that the tip end of the rotor contacts the article to be joined. In a friction stir welding device for softening a part by frictional heat due to rotation and stirring to join objects to be welded, the rotor has a pin that is inserted into the rotor and is displaceable in a rotation axis direction. The friction stir welding apparatus is characterized by spot welding the objects to be welded.

Further, according to the present invention, the rotor rotating at a high speed is moved in the direction of the rotation axis to press the tip of the rotor against the article to be joined, and the contact portion between the tip of the rotor and the article to be joined is rotated. In a friction stir welding apparatus that softens by frictional heat, stirs, and spot-joins objects to be welded, (a) the rotor has a pin that is inserted into the rotor and is displaceable in a rotation axis direction, (B) A friction stir welding apparatus including means for relatively displacing the rotor and the pin in the direction of the rotation axis. Further, according to the present invention, a pin is inserted into the rotor so as to be displaceable in the rotation axis direction, the rotor rotating at a high speed is moved in the rotation axis direction, the rotor tip is pressed against the article to be bonded, and the rotor tip is moved. The friction stir welding method is characterized in that a contact portion between the portion and the object to be welded is softened by frictional heat due to rotation and stirred to perform spot welding of the object to be welded. According to the present invention, since the pin is movably provided, it is possible to perform spot joining without forming a large cavity by retracting the pin at the end of spot joining.

Further, the present invention is characterized in that a cylindrical ring portion is formed at the tip of the rotor, and the pin is an inner shaft that is inserted into the ring portion so as to be displaceable.

According to the present invention, by making the pin cylindrical, it is possible to increase the contact area of the pin with the article to be joined, to efficiently generate frictional heat, and to improve the joining efficiency.

Further, the present invention is characterized in that the fixed state and the movable state of the pin are switched by switching the rotation direction of the rotor.

According to the present invention, by switching the rotation direction, the pin can be switched between the fixed state and the movable state, and the control is easy.

Further, according to the present invention, the pins are joined in a state of protruding from the tip of the rotor, and then the pin is retracted so that the tip of the rotor is flat and pressed again for a predetermined time with a predetermined pressing force. Is characterized by.

According to the present invention, since the pins are retracted and re-bonded, it is possible to bond by applying a pressing force even after the bonding is completed, and the bonding quality can be improved. Rejoining means, as will be described later, first, joining is performed with the pin protruding from the rotor tip, and then the pin is retracted and pressed again for a predetermined time with a predetermined pressing force, thus It means performing joining or continuous joining.

Further, the present invention is characterized in that when the pressing is performed again, the pin is fixed.

According to the present invention, when the pins are rejoined, the pins are retracted and switched to the fixed state, so that the pins can be rejoined without forming a large cavity.

Further, according to the present invention, a pin is inserted into the rotor so as to be displaceable in the direction of the rotation axis, the rotor rotating at a high speed is moved in the direction of the rotation axis, and the tip of the rotor is pressed against the object to be joined. A friction stir welding method in which a contact portion between a rotor tip and the object to be welded is softened by frictional heat generated by rotation and is agitated to weld the object to be welded, wherein the pin is projected from the rotor tip. The objects to be joined are continuously joined in the state, and at the joining end point,
The friction stir welding method is characterized in that the pin is retracted, the tip of the pin is displaced to the flat surface of the rotor tip, the pin is fixed, and the pin is pressed again for a predetermined time with a predetermined pressing force.

According to the present invention, in continuous joining, the pin is displaced and re-joined at the joining end point, so that it is possible to press and join even at the joining end point. It is possible to prevent the deterioration of the joining quality.

[0020]

According to the present invention, in continuous joining, by retracting the pin at the joining end point and switching to the fixed state, it is possible to rejoin without forming a large cavity at the joining end point.

[0022]

According to the present invention, by displacing the pin to a flat surface and joining at this flat surface, it is possible to join without forming a large cavity.

[0024]

1 is a sectional view showing the structure of a friction stir welding apparatus 1 according to an embodiment of the present invention. The friction stir welding apparatus 1 of this embodiment is used as a spot welding gun by being attached to the wrist of a 6-axis vertical articulated robot, for example.

The friction stir welding apparatus 1 includes a gun arm 5 and
The rotor 2 is supported rotatably around the rotation axis L and linearly movable along the rotation axis L. Further, a servo motor 6 which is a rotary drive source and an induction motor 7 which is a linear drive source are fixedly attached to the gun arm 5. The linear drive source may be a servo motor.

The rotor 2 comprises a rotor body 3 and a rotor holding member 4. The rotor main body 3 is attached and fixed to the lower end portion of the rotor holding member 4 with the rotation axis L being coaxial. The rotor body 3 has a tapered tip, and a cylindrical shoulder portion 11 is formed at the tip. A pin 12 is inserted into the rotor 2 along the rotation axis L, and a columnar pin 12 is provided so as to be retractable from the center of the shoulder portion 11. The gun arm 5 is bent into an L-shape, and a bent end portion is provided with a receiving portion 36 that is arranged to face the rotor tip.

The rotor holding member 4 is inserted into a cylindrical holder 15 having a bottom, and is held so as to be able to move straight in the direction of the rotation axis L. Rotational force is transmitted from the induction motor 7 from the outer peripheral portion of the holder 15. For more details,
A spline 17 is formed on the outer periphery of the holder 15, and a spline receiver 18 into which the spline 17 is fitted is rotatably supported by a bearing 19 fixedly supported by the gun arm 5. A belt wheel 20 is fixed to an output shaft of an induction motor 7 fixedly supported by the gun arm 5, a belt wheel is formed on the outer circumference of the spline receiver 18, and a V belt 21 is wound from the belt wheel 20 to the belt wheel 20. . With such a configuration, the rotor 2 can be driven to rotate about the rotation axis L by rotating the induction motor 7. Further, since the rotational force is transmitted via the spline 17, the rectilinear movement of the rotor 2 in the rotation axis L direction is allowed.

The straight driving force of the rotor 2 is given from the upper end of the holder 15. More specifically, the coupling member 26 is coupled to the holder 15 at the upper end of the holder 15 via the bearing 25 so as to be rotatable about the rotation axis L and prevented from being displaced in the rotation axis L direction. Gun arm 5
A linear guide 27 is fixed in parallel to the rotation axis L, and the linear guide 27 supports the connecting member 26 on the gun arm 5 so as to be linearly movable in the rotation axis L direction. Further, the bearing 16 which holds the lower portion of the rotor holding member 4 rotatably around the rotation axis L is also supported by the linear guide 27 so as to be linearly movable parallel to the rotation axis L.

On the upper part of the connecting member 26, a nut 30 centering on the rotation axis L is fixed to the connecting member 26. A screw shaft 31 is screwed into the nut 30, and the screw shaft 3
1 is rotatably supported around an axis L by a bearing 32 fixedly supported by the gun arm 5. Screw shaft 3
A toothed belt wheel 33 is fixed to the upper end portion of 1, and a toothed belt wheel 35 is also fixed to the output shaft of the servomotor 6 fixedly supported by the gun arm 5. These belt wheels 33,3
The timing belt 34 is wound around for 5 minutes. Therefore, by rotating the servo motor 6,
The screw shaft 31 is rotated around the axis line L, whereby
The rotor 2 can be moved straight along the rotation axis L. Further, the connecting member 26 and the holder 15 have a bearing 25.
, The rotor 2 can be moved straight in the direction of the rotation axis L while rotating at high speed. Further, the moving direction can be switched by changing the rotation direction of the servo motor 6.

A pin insertion hole 40 penetrates the rotor body 3 and the rotor holding member 4 along the rotation axis L, and the pin 12 is inserted into the pin insertion hole 40. The upper end of the pin 12 is fixed to the top wall 15 a of the holder 15. Pin 1
The tip of 2 projects from the center of the shoulder 11.

The rotor holding member 4 is inserted into the holder 15, and a spring 41 is interposed between the upper end surface 4a and the top wall 15a of the holder 15. The spring 41 urges the rotor holding member 4 downward along the axis L (on the side away from the top wall 15a of the holder 15).

Further, the holder 15 and the rotor holding member 4 are switched between the movable state and the fixed state by the switching mechanism 42, and when the holder 15 and the rotor holding member 4 are in the movable state, the rotor holding member 4 is moved to the holder 15 state. Is movable in the direction of the rotation axis L, and is in the fixed state,
Movement in the rotation axis L direction is fixed.

FIG. 2 is a front view showing the switching mechanism 42. The switching mechanism 42 includes an L-shaped notch 43 formed in the holder 15 and a locking projection 44 that projects radially outward from the rotor holding member 4 and fits into the notch 43. The notch 43 is composed of a horizontal notch 45 extending in the circumferential direction around the rotation axis L and a vertical notch 46 extending in the up-down direction in parallel with the rotation axis L. The notch 43
The locking protrusions 44 can move along. When the locking protrusion 44 is in the vertical cutout 46, the rotor holding member 4 is movable along the rotation axis L, and when in the horizontal cutout 45, the rotor holding member 4 rotates. Axis L
Movement in the direction is blocked, and the state becomes fixed. Such a switching mechanism 42 is formed at two locations on both sides of the rotation axis L.

Next, the joining method of the friction stir welding apparatus 1 will be described with reference to the switching mechanism 42 shown in FIG. 3 and the time chart shown in FIG. Here, the case of spot joining will be described. Therefore, the two workpieces are horizontally overlapped, and first, the robot positions the workpiece so that the joining point of the workpieces is placed on the receiving portion 36 of the friction stir welding apparatus 1 (spot welding gun).

(1) In the initial state, it is assumed that the rotor 2 is at the origin, which is separated upward from the work by a predetermined distance.
Further, in the switching mechanism 42, it is assumed that the position shown in FIG. 3A, that is, the locking convex portion 44 is located at the end portion A of the lateral cutout portion 45. At this time, the pin 12 does not project from the shoulder portion 11 at the tip of the rotor, and the lower end surface of the shoulder portion 11 is flat.

(2) The servo motor 6 which is a linear drive source is driven. Then, the holder 15 and the rotor 2 slide and descend via the connecting member 26.

(3) The holder 15 is rotated in the forward direction by the induction motor 7, which is a rotational drive source, that is, rotated in the + direction in FIG. 3 (2).

(4) When the holder 15 is rotated in the + direction, the locking convex portion 44 moves from the position A to the position B by the notch 43. That is, the rotor holding member 4 moves to the vertical cutout portion 46, and is in a state of being linearly movable with respect to the holder 15 in the rotation axis L direction. Not only when the rotation is started at this stage, but when the welding is continuously performed, the forward rotation at the end of the previous welding is maintained. In this state, the rotor 2 continues to descend further.

(5) Rotor tip, that is, shoulder portion 1
The lower end surface of 1 contacts the work. Here, the switching mechanism 4
2 assumes the case where the locking projection 44 is moved to the B position in (4), but when it is not moved to B in (4), when the shoulder part 11 abuts the work. , The rotor holding member 4 by the frictional force between the work and the shoulder portion 11.
Tends to move in the negative direction relative to the holder 15. A frictional force is also generated between the holder 15 and the rotor holding member 4, but by setting the frictional force between the work and the shoulder portion 11 to be larger, the rotor holding member 4 rotates in the − direction. Then, the locking protrusion 44 is locked at the position B, and the switching mechanism 42 is reliably switched to the movable state.

(6) When the holder 15 is further lowered and pressed by the servo motor 6, the switching mechanism 42 is in a movable state, so that the spring 41 is compressed and the rotor holding member 4 is moved relative to the holder 15. And the pin 12 starts to protrude from the tip of the shoulder portion 11. In this way, the pressing is performed until the predetermined pressing force is reached. In this manner, the frictional heat of the shoulder portion 11 softens the joint point of the work, and the pushed-out pin 12 is inserted into the work. Along with this, the shoulder portion 11
And the pin 12 rotates at a high speed, whereby the base material is agitated and plastic flow occurs. The pressing force is determined by the current value of the servo motor 6.

(7) When the predetermined pressing force is reached, the pressing force is applied for a predetermined time. As a result, the work is further stirred, and the two works are integrated at the joining point. At this time, the coil spring 41 may contract until there is no gap, or there may be a margin to contract. In addition, the switching mechanism 42
Is at a position C where the locking protrusion 44 is the upper end of the vertical notch 46.
May be reached, or there may be room.

(8) After a lapse of a predetermined time, the servo motor 6 is rotated in the reverse direction to raise the holder 15. Then, due to the action of the spring 41, only the pin 12 rises in a state where the tip of the shoulder portion 11 maintains contact with the workpiece,
2 is drawn into the shoulder portion 11. At this time, the softened base material enters after the pin 12 is drawn in, and the cavity is closed. In this way, the holder 15 is pulled up and stopped until the locking projection 44 is locked at the position B. At this time, it is preferable that the tip of the shoulder portion 11 is in contact with the work and there is slight friction.

(9) Here, the induction motor 7, which is a rotary drive source, is rotated in the reverse direction to rotate the holder 15 in the negative direction. At this time, by setting the frictional force between the workpiece and the rotor tip end to be larger than the frictional force between the rotor holding member 4 and the holder 15, the holder 15 causes the rotor holding member 4 to move.
Rotate in the-direction relative to. In this way
The locking projection 44 moves to the position A, and the switching mechanism 42 switches to the fixed state. Although the rotation drive source is the induction motor in this embodiment, it can be reversed in a short time by using the servo motor.

(10) Then, in this state, the servo motor 6 is reversed and pressed again. At this time, since the pin 12 is in the retracted state, the end of the shoulder portion 11 is pressed in a flat state. In this way, the pressing force is applied for a predetermined time. This further closes the cavity. Further, at this time, the switching mechanism 42 is in a fixed state, and the pressing force from the servo motor 6 directly acts,
The spring force of the spring 41 does not intervene.

(11) After the pressing is completed, the servo motor 6 is rotated in the reverse direction to raise the holder 15 and the rotor 2.

(12) After the rotor 2 is separated from the work,
The induction motor 7 is returned to the normal rotation (+ direction).

In this way, spot joining is completed. When the spot joining is continuously performed, the robot positions the joining device 1 at the next joining point, and the work from (1) is performed again in order.

FIG. 5 is a diagram (A) showing a work cross section after the joining is completed in the conventional spot joining and a work cross section after the joining according to the present invention. Conventionally, as shown in P1 of (A), a large cavity is formed by the pin, but in the present invention, since the pin is re-joined while being retracted into the shoulder portion 11, as shown in P2 of (B). In addition, the cavity can be made smaller than the conventional one. Further, the shoulder portion 11 has a concave center as shown in (B),
The outer periphery is formed to project. by this,
In the above step (8), only the tip of the shoulder 11 can be brought into contact with the work.

Although the case of spot welding has been described in the present embodiment, the friction stir welding apparatus 1 can also be applied to the case of continuous welding. In this case, in the pressing in the step (7) described above, the robot uses the joining device 1
Is moved along the joining line set on the workpiece. As a result, continuous joining is performed. Even in this case, the cavity formed at the joining end point can be made small by re-joining at the joining end point.

FIG. 6 is a view showing the structure of a friction stir welding apparatus 50 which is another embodiment of the present invention. The friction stir welding apparatus 50 of this embodiment is the friction stir welding apparatus 1 described above.
Since it has almost the same structure as the above, the same reference numerals are given to the corresponding structures and the description thereof will be omitted.

A member corresponding to the rotor holding member 4 of the friction stir welding apparatus 1 is integrated with the holder 53 in this embodiment, and the rotational force of the induction motor 7 is transmitted from the outer circumference of the holder 53. . Also, this holder 53
The rotor 54 is attached to the lower end of the.

The greatest feature of this embodiment is that a cylindrical ring-shaped pin is used instead of a cylindrical pin. Therefore, at the tip of the shoulder portion 11 of the rotor 54, the cylindrical ring portion 51 projects around the rotation axis L. An inner shaft 52 having an outer diameter corresponding to the inner diameter of the cylindrical ring portion 51 is movably inserted into the ring portion 51.

A pin insertion hole 55 is formed in the rotor 54 and the holder 53 along the rotation axis L, and the inner shaft 52 is inserted into the pin insertion hole 55. A cylindrical space 56 is formed in the upper portion of the holder 53, and a cylindrical body 57 is fitted in the space so as to be movable along the axis L. This column 57
The inner shaft 52 is fixed to the lower end of the cylindrical body 57 and the inner shaft 5.
It moves together with 2. Further, the spring 41 is interposed between the cylindrical body 57 and the top wall 53a of the holder 53.

Like the friction stir welding apparatus 1, the holder 53
A switching mechanism 42 is provided on the outer peripheral portion of the. Similarly to the above, the switching mechanism 42 also includes an L-shaped notch 43 formed in the holder 53 and a locking convex portion 44 fitted in the notch 43, and the locking convex portion 44 is the present embodiment. In the form, it is formed into a cylindrical body 57.

When the switching mechanism 42 is in the fixed state, the tip of the inner shaft 52 becomes flush with the tip of the ring portion 51 and becomes flat, and the switching mechanism 42 is in a movable state and the inner shaft 52 moves upward. Then, it becomes a ring type pin.

Since this friction stir welding apparatus 50 can also perform spot welding by operating in the same manner as the friction stir welding apparatus 1 described above, referring to the time chart of FIG. The control operation of the device 50 will be described below.

(1) In the initial state, the switching mechanism 42 is in a fixed state. At this time, the tip of the inner shaft 52 is flush with the ring portion 51.

(2) Next, the servo motor 6, which is a linear drive source, is driven. Then, the holder 53 and the rotor 5
4 slides down. At this time, the rotor 54 and the inner shaft 52 are integrally lowered.

(3) Next, the holder 53 is rotated in the forward direction by the induction motor 7 which is a rotary drive source, that is, as shown in FIG.
Rotate in the + direction with (2).

Then, (4), the holder 53 rotates in the + direction relative to the cylindrical body 57, the locking convex portion 44 moves and is locked at the B position, and the switching mechanism 42 is in the movable state. Becomes Further, the inner shaft 52 and the rotor 54 rotate together. In this state, the rotor 54 continues to descend.

(5) The tip of the rotor, that is, the tip of the ring portion 51 and the tip of the inner shaft 52 is in contact with the work. And the inner shaft 52
A frictional force is generated between the work and the work. Then, the holder 53
The frictional force between the cylindrical body 57 and the columnar body 57 is compared with the frictional force between the work and the inner shaft 52, and the latter is set to be larger, so that the inner shaft 52 tends to stop. As the holder 53 rotates in the + direction, the locking protrusion 4 is pressed in (4).
4 does not reach the B position, the locking protrusion 4
4 is surely moved to the B position and is switched to the movable state.

(6) When the holder 53 is further lowered and pressed by the servo motor 6, the switching mechanism 42 is in a movable state, so that the spring 41 is compressed and the inner shaft 52 is relatively moved with respect to the ring portion 51. Pull in. At this time, the locking protrusion 42 moves upward. In this way, the pressing is performed until the predetermined pressing force is reached.

(7) When the predetermined pressing force is reached, the pressing force is applied for a predetermined time. The pressing force is determined by the current value of the servo motor 6. At this time, the coil spring 4
No. 1 may shrink until there is no gap, and there may be a margin to shrink. In addition, the switching mechanism 42 includes the locking convex portion 44.
May reach the position C which is the upper end of the vertical cutout portion 46, and may have a margin.

(8) After a lapse of a predetermined time, the servo motor 6 is rotated in the reverse direction to raise the holder 53. Then, by the action of the spring 41, only the rotor 54 rises and the inner shaft 52 is drawn into the ring portion 51 in a state where the tip end of the inner shaft 52 maintains contact with the work. In this way, the switching mechanism 42 raises the holder 53 to the original position where the locking projection 44 descends and is locked at the B position. It is preferable that there is slight friction between the work and the tip of the inner shaft 52.

(9) Here, the induction motor 7, which is the rotary drive source, is rotated in the reverse direction to rotate the holder 53 in the negative direction. At this time, the frictional force between the work and the tip of the inner shaft 52 is
By setting the friction force to be larger than the frictional force between the holder 53 and the columnar body 57, the holder 53 rotates in the negative direction relative to the columnar body 57. In this way, the locking protrusion 4
4 moves to the A position, and the switching mechanism 42 switches to the fixed state.

(10) Then, in this state, the servo motor 6 is reversed and pressed again. At this time, the tip end of the inner shaft 52 and the tip end of the ring portion 51 are flush with each other and are pressed in a flat state. In this way, the pressing force is applied for a predetermined time.

(11) After the pressing is completed, the servo motor 6 is rotated in the reverse direction to raise the holder 53 and the rotor 54.

(12) After the rotor 54 is separated from the work, the induction motor 7 is returned to the normal rotation (+ direction).

Spot joining is performed in this manner. FIG. 7 (A) is a view showing a cross section of the work after joining when only the ring type pin is used, and FIG. 7 (B) is after joining when using the friction stir welding device 50 of the present invention. It is a figure which shows the workpiece cross section of. (A) and (B) cavities P3, P
As can be seen by comparing No. 4, by using the present invention, the size of the cavity after joining can be reduced.

Further, by using the ring type pin, the contact area with the work can be made larger than that of the ordinary columnar pin, and the generation efficiency of frictional heat and the stirring efficiency can be improved.

In each of the above-mentioned embodiments, the pin 12 is used.
Alternatively, the fixed / movable switching of the inner shaft 52 is performed by reversing the rotation direction, but the following method may be used.

(1) A servo motor for driving the pin 12 or the inner shaft 52 is separately provided, and the rotation of this servo motor is converted into a rectilinear motion to independently drive it.

(2) The mechanical ON / OFF mechanism is used to switch the pin / inner shaft between fixed / movable by ON / OFF.

(3) The rotation of the motor 7 is appropriately turned on / off by a separate electromagnetic clutch to convert the rotational force into a linear motion and switch the pin 12 or the inner shaft 52 between fixed / movable.

Further, in the above-described embodiment, (1) to
In each step of (12), the rotation speed of the rotor is constant, for example, 2000 rpm in the present embodiment, but may be changed appropriately.

For example, (1) to (5) 500 rpm (6) 1000 rpm (7) 2000 rpm (8) 1000 rpm (9) -800 rpm (10) -1600 rpm (11) -500 rpm (12) 500 rpm By doing so, the joining quality can be further improved.

[0077]

As described above, according to the present invention, since the pin is movably provided, it is possible to perform spot bonding without forming a large cavity by retracting the pin at the end of spot bonding. is there.

Further, according to the present invention, by making the pin cylindrical, it is possible to increase the contact area of the pin with the article to be joined and efficiently generate frictional heat, thus improving the joining efficiency.

Further, according to the present invention, the pin can be switched between the fixed state and the movable state by switching the rotation direction, which facilitates the control.

Further, according to the present invention, since the pins are retracted and re-bonded, it is possible to apply the pressing force even when the bonding is completed, and the bonding quality can be improved.

Further, according to the present invention, when the pins are rejoined, the pins are retracted and switched to the fixed state, so that the pins can be rejoined without forming a large cavity.

Further, according to the present invention, in continuous joining,
Since the pin is displaced and re-joined at the joining end point, it is possible to prevent the joining quality from being deteriorated at the joining end point of continuous joining as in the conventional technique.

Further, according to the present invention, in continuous joining,
By retracting the pin at the joining end point and switching to the fixed state, it is possible to rejoin without forming a large cavity at the joining end point.

Further, according to the present invention, the pins can be displaced to a flat surface, and the flat surfaces can be bonded to each other, whereby the bonding can be achieved without forming a large cavity.

[Brief description of drawings]

FIG. 1 is a diagram showing a structure of a friction stir welding apparatus 1 according to an embodiment of the present invention.

FIG. 2 is a front view showing a switching mechanism 42.

FIG. 3 is a diagram showing a state of a switching mechanism 42 at the time of joining work.

FIG. 4 is a time chart showing a joining method of the friction stir welding apparatus 1.

FIG. 5 is a view showing a cross section of a work after joining in a conventional apparatus and a cross section of a work after joining when the present invention is used.

FIG. 6 is a view showing the structure of a friction stir welding apparatus 50 using a ring pin according to another embodiment of the present invention.

FIG. 7 is a view showing a cross section of a work after joining of a conventional device using a ring type pin and a cross section of a work after joining using a friction stir welding device 50 of the present invention.

[Explanation of symbols]

1,50 Friction stir welding device 2,54 rotor 12 pin 42 switching mechanism 51 Ring part 52 inner shaft

Claims (10)

(57) [Claims] 1. A rotor rotating at a high speed is moved in the direction of the rotation axis to press the rotor tip against an article to be joined, and the contact portion between the rotor tip and the article is rotated by friction heat. In a friction stir welding apparatus that softens and stirs to join objects to be joined, the rotor has a pin that is inserted through the rotor and is displaceable in the direction of the rotation axis, and spot-joins the objects to be joined. A friction stir welding device characterized in that 2. The friction stir welding apparatus according to claim 1, wherein a cylindrical ring portion is formed at the tip of the rotor, and the pin is an inner shaft that is displaceably inserted into the ring portion. . 3. By switching the rotation direction of the rotor,
The friction stir welding apparatus according to claim 1 or 2, wherein the pin is switched between a fixed state and a movable state. 4. A rotor rotating at a high speed is moved in the direction of the rotation axis to press the rotor tip against an article to be joined, and the contact portion between the rotor tip and the article is rotated by friction heat. In a friction stir welding apparatus for softening and stirring to spot-join objects to be welded, (a) the rotor has a pin that is inserted into the rotor and is displaceable in a rotation axis direction, (b) A friction stir welding apparatus comprising means for relatively displacing the rotor and the pin in the rotation axis direction. 5. A rotor is provided so as to be displaceable in the rotation axis direction by inserting a pin into the rotor, the rotor rotating at a high speed is moved in the rotation axis direction, and the rotor tip end portion is pressed against an article to be joined, whereby A friction stir welding method, characterized in that a contact portion between the portion and the object to be welded is softened by frictional heat generated by rotation and stirred to perform spot welding of the object to be welded. 6. The friction stir welding method according to claim 5, wherein a cylindrical ring portion is formed at a tip of the rotor, and the pin is an inner shaft displaceably inserted in the ring portion. . 7. The pin is joined in a state of protruding from the tip of the rotor, and then the pin is retracted to make the tip of the rotor flat and again pressed with a predetermined pressing force for a predetermined time. The friction stir welding method according to claim 5 or 6. 8. The friction stir welding method according to claim 7, wherein the pin is fixed when the pressing is performed again. 9. A rotor is provided so as to be displaceable in the rotation axis direction by inserting a pin into the rotor, the rotor rotating at a high speed is moved in the rotation axis direction, and the rotor tip is pressed against an object to be joined, whereby the rotor tip is moved. Is a friction stir welding method in which a contact portion between a welding part and the object to be welded is softened by frictional heat generated by rotation and is agitated to join the objects to be welded. It is characterized in that the joined objects are continuously joined, and at the joining end point, the pin is retracted, the tip of the pin is displaced to the flat surface of the rotor tip, the pin is fixed, and the pin is pressed again for a predetermined time with a predetermined pressing force And friction stir welding method. 10. The friction stir welding method according to claim 5, wherein the pin is switched between a fixed state and a movable state by switching a rotation direction of a rotor.